1. Field of the Invention
The present invention relates generally to athletic equipment and, more particularly, to an exercising device for a barbell.
2. Description of the Prior Art
In one type of speed weight lifting exercise, a barbell is moved by the weight lifter during a single downward and return upward movement. The downward movement is known as eccentric movement while the upward movement is known as concentric movement.
It is well kown that the muscles of the human body are capable of lifting between twenty and fifty percent more weight during eccentric movement than during concentric movement. Thus, for maximum exercising efficiency, the weight on the barbell should be between twenty and fifty percent greater during eccentric movement than during concentric movement.
In the previously known barbells the weight of the barbell, while adjustable between different exercises or exercise routines, is fixed during any particular exercise routine. Consequently, it is not possible to obtain maximum exercising efficiency since either the preferred weight for eccentric movement is too small, the preferred weight for concentric movement is too large, or both.